In Oozie, which component is responsible for executing a specific task within a workflow?
- Oozie Action
- Oozie Coordinator
- Oozie Executor
- Oozie Launcher
In Oozie, the component responsible for executing a specific task within a workflow is the Oozie Action. It represents a unit of work, such as a MapReduce job or a Pig script, and is defined within an Oozie workflow.
What is often the cause of a 'FileNotFound' exception in Hadoop?
- DataNode Disk Full
- Incorrect Input Path
- Job Tracker Unavailability
- Namenode Failure
An 'FileNotFound' exception in Hadoop is often caused by an incorrect input path specified in the job configuration. It's essential to verify and provide the correct input path to ensure that the Hadoop job can locate and process the required data.
In a scenario involving large-scale data transformation, which Hadoop ecosystem component would you choose for optimal performance?
- Apache Flume
- Apache HBase
- Apache Hive
- Apache Spark
In scenarios requiring large-scale data transformation, Apache Spark is often chosen for optimal performance. Spark's in-memory processing and efficient data processing engine make it suitable for handling complex transformations on large datasets with speed and scalability.
In a scenario requiring the migration of large datasets from an enterprise database to Hadoop, what considerations should be made regarding data integrity and efficiency?
- Data Compression and Decompression
- Data Consistency and Validation
- Network Bandwidth and Latency
- Schema Mapping and Transformation
When migrating large datasets to Hadoop, considerations for data integrity and efficiency should include ensuring data consistency and validation. It involves verifying that data is accurately transferred, maintaining its integrity during the migration process.
When dealing with skewed data, ____ in MapReduce helps distribute the load more evenly across reducers.
- Counters
- Load Balancing
- Replication
- Speculative Execution
In the context of dealing with skewed data in MapReduce, Speculative Execution is a technique that helps distribute the load more evenly across reducers. It involves launching backup tasks for slow-running tasks on different nodes to ensure timely completion.
When configuring HDFS for a high-availability architecture, what key components and settings should be considered?
- Block Size
- MapReduce Task Slots
- Quorum Journal Manager
- Secondary NameNode
Configuring HDFS for high availability involves considering the Quorum Journal Manager, which ensures consistent metadata updates. It replaces the Secondary NameNode in maintaining the edit logs, enhancing fault tolerance and reliability in a high-availability setup.
Which tool in the Hadoop ecosystem is best suited for real-time data processing?
- HBase
- MapReduce
- Pig
- Spark
Apache Spark is well-suited for real-time data processing in the Hadoop ecosystem. It offers in-memory processing and supports iterative algorithms, making it faster than traditional batch processing with MapReduce. Spark is particularly advantageous for applications requiring low-latency data analysis.
In Hadoop's MapReduce, the ____ phase occurs between the Map and Reduce phases.
- Combine
- Merge
- Shuffle
- Sort
In Hadoop's MapReduce, the Shuffle phase occurs between the Map and Reduce phases. During this phase, the output from the Map phase is shuffled and sorted before being sent to the Reduce tasks for further processing.
In a scenario where data consistency is critical between Hadoop and an RDBMS, which Sqoop functionality should be emphasized?
- Full Import
- Incremental Import
- Merge Import
- Parallel Import
In situations where data consistency is critical, the Incremental Import functionality of Sqoop should be emphasized. It allows for the extraction of only the new or updated data since the last import, ensuring consistency between Hadoop and the RDBMS.
Which feature of Apache Flume allows for the dynamic addition of new data sources during runtime?
- Channel Selectors
- Flume Agents
- Source Interceptors
- Source Polling
The feature in Apache Flume that allows for the dynamic addition of new data sources during runtime is 'Source Interceptors.' These interceptors can be configured to modify, filter, or enrich events as they enter the Flume pipeline, facilitating the seamless integration of new data sources without interrupting the data flow.